Blood pressure variability, time in target range, and cognitive impairment among hypertensive adults: a cross-sectional study in a Southeast Asian multiethnic population

Hypertension is a major risk factor for cognitive decline, but the relationships of blood pressure variability (BPV), time in target range (TTR), and hypertension phenotypes with cognitive impairment remain unclear, particularly in multiethnic Southeast Asian populations. This study evaluated the associations of cognitive impairment with BP indices, BPV, TTR, and hypertension phenotypes in a multiethnic hypertensive population in Malaysia. A cross-sectional study was conducted among 730 hypertensive adults (mean age ± SD: 66.1 ± 10.0 years; 56.6% females; 40.1% Chinese, 29.2% Malays, and 30.7% Indians/Others). Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). Clinic and home BP measurements, BPV indices (standard deviation [SD], coefficient of variation [CV], variability independent of the mean [VIM], and average real variability [ARV]), and TTR were analysed. The mean MoCA score was 24.27 ± 0.19, with 357 participants (48.9%) classified as cognitively impaired. In unadjusted analyses, cognitive impairment was associated with significantly higher SD (7.34 ± 2.79 vs. 6.66 ± 3.25 mmHg, p = 0.028), VIM (7.30 ± 2.69 vs. 6.68 ± 3.25, p = 0.042), and ARV (7.92 ± 3.36 vs. 7.17 ± 3.74 mmHg, p = 0.038). However, these associations were not significant after adjustment for confounders. Mean BP levels, CV, VIM, ARV, SD, and TTR were not independently associated with cognitive impairment. TTR was insignificantly lower in participants with cognitive impairment (67.43 ± 4.43%) vs. normal (77.35 ± 4.28%) after adjustment. Cognitive status did not differ across hypertension phenotypes. Diabetes mellitus was more prevalent among participants with cognitive impairment (54.9% vs. 42.7%, p = 0.001). Education attainment (OR = 0.395, 95% CI: 0.309–0.504, p < 0.001) and ethnicity (OR up to 2.17, p < 0.001) were independently associated with cognitive impairment. Cognitive impairment was prevalent among hypertensive adults in this multiethnic Malaysian cohort. BP characteristics, including BPV, BP levels, and TTR, were not independently associated with cognitive impairment after adjustment. Ethnicity and education attainment were stronger determinants of cognitive status. Longitudinal studies are needed to clarify the impact of BP patterns on cognitive decline. ClinicalTrials.gov NCT04342468; https://clinicaltrials.gov/study/NCT04342468 .